Renal Denervation vs. Spironolactone in Resistant Hypertension: Effects on Circadian Patterns and Blood Pressure Variability

Background: Sympathetic renal denervation (SRD) has been proposed as a therapeutic alternative for patients with resistant hypertension not controlled on pharmacological therapy. Two studies have suggested an effect of SRD in reducing short-term blood pressure variability (BPV). However, this has not been addressed in a randomized comparative trial. We aimed to compare the effects of spironolactone and SRD on circadian BP and BPV.

Methods: This is a post-hoc analysis of a randomized trial in 24 true resistant hypertensive patients (15 men, 9 women; mean age 64 years) comparing 50mg of spironolactone (n = 13) vs. SRD (n = 11) on 24-hour BP. We report here the comparative effects on daytime (8 am-10 pm) and nighttime (0 am-6 am) BP, night-to-day ratios and BP and heart rate variabilities (SD and coefficient of variation of 24-hour, day and night, as well as weighted SD and average real variability (ARV)).

Results: Spironolactone was more effective than SRD in reducing daytime systolic (P = 0.006), daytime diastolic (P = 0.006), and nighttime systolic (P = 0.050) BP. No differences were observed in the night-to-day ratios. In contrast, SRD-reduced diastolic BPV (24 hours, daytime, nighttime, weighted, and ARV; all P < 0.05) with respect to spironolactone, without significant differences in systolic BPV.

Conclusion: Spironolactone is more effective than SRD in reducing ambulatory BP. However, BPV is significantly more reduced with SRD. This effect could be important in terms of potential prevention beyond BP reduction and deserves further investigation.